You will need a minimum of 153 slabs. However, that answer assumes that the area to be covered is "well behaved" and that you are happy to use offcuts and chippings so that part of the area will look like a mosaic. If these conditions are not met, you should consider getting 5% extra slabs.
If, for example, the 55 sq metre area is in the form of a rectangle which is 550 mm wide and 100 metres long it may be easier to cover it using 167 trimmed slabs in a long line rather than use offcuts which are 5 mm wide.
305.56
Depends on the linear dimensions of both the slabs and the ground.
1 slab of 1200 metres x 450 metres will certainly cover 1600 square metres. You may have trouble moving it into position, though.
0.6 x 0.6 = 0.36 m2
It requires 183 450x450mm tiles to cover 37 square meters of area. However this does not take into account waste. For laying ceramic tile on concrete the rule of thumb is to assume about 10% extra for waste, so you would need about 200 tiles.
305.56
The answer will depend on the size of the patio slabs.
23.41 sq m
279 sq ft = 25.92 sq metres so, at 0.36 sq metres apiece, 72 slabs. This assumes that all offcuts can be used - a totally unrealistic assumption in real life.
600mm is 0.6m, and 450mm is 0.45m, so one flag is 0.27 sq metre. Therefore 4 flags to the square metre
0.6 x 0.3 = 0.18 square metres 5/0.18 = 27.78 tiles, or 28 if being practical
14
Depends on the linear dimensions of both the slabs and the ground.
0.6 m 600mm > 60 cm > 0.6 m :]
600mm = 60cm
1 slab of 1200 metres x 450 metres will certainly cover 1600 square metres. You may have trouble moving it into position, though.
20 I believe